The cars entered the lane, which runs down the middle of Interstate 10 in west Houston and is walled off from the mainlanes, through a gate at a park-and-ride lot near Highway 6, Metropolitan Transit Authority spokeswoman Maggi Stewart said.

The HOV lane usually runs inbound throughout the morning rush but was closed early, about 10 a.m., so it could be reversed at 11 a.m. to accommodate outbound holiday traffic. Three cars somehow entered the lane the wrong way around 10:50 a.m., Stewart said.

Metro police tracked down the cars and escorted them out of the lanes. Outbound traffic was not seriously disrupted.